The present invention relates to an electrophotographic copying machine and, more particularly, to the structure of a heat roller in a heat fixing device in an electrophotographic copying machine.
In the surface of a conventional heating roller in a heat fixing device in an electrophotographic copying machine, a heat-resistive resin is coated thereon to improve easy release to toner particles from the surface of a heated fixing roller and a compression roller. However, the resin material to be coated on the rollers is dielectric so that the heated fixing roller itself is charged to absorb the tonner particles, resulting in an offset of the toner particles. The resin may become electrically conductive by the addition of conductive particles. However, such mixing of the conductive particles may damage the release property and mechanical strength.